Cancellous bone volume and structure in the forearm: noninvasive assessment with MR microimaging and image processing.
OBJECTIVE
To develop and apply a method for the derivation of cancellous bone architectural parameters from in vivo magnetic resonance (MR) images of the distal radius and to evaluate these parameters as predictors of vertebral fracture status in osteopenia.


METHODS
MR images (137 x 137 x 500-micron3 voxel size) were acquired with a three-dimensional partial flip-angle spin-echo pulse sequence in the distal radius of 36 women. Subjects were classified as healthy or with osteoporosis on the basis of vertebral deformity and bone mineral density (BMD). Images rated as of adequate quality in 20 subjects were processed with a method that is applicable in the limited spatial resolution regime. The method relies on histogram deconvolution to obviate binary segmentation. Cancellous bone structure was treated as a quasi-regular lattice and analyzed with spatial autocorrelation, yielding parameters that quantify intertrabecular spacing, contiguity, and a measure of longitudinal alignment called tubularity.


RESULTS
Whereas neither BMD nor any of the structural parameters individually correlated significantly with vertebral deformity fraction, a simple function that involved tubularity and longitudinal spacing predicted deformity fraction well (r = .78, P < .005).


CONCLUSIONS
Histomorphometric parameters characterizing cancellous bone in the distal radius can be derived from in vivo MR microimages and are predictive of vertebral deformity.
Wehrli
F W
FW
Department of Radiology, University of Pennsylvania Medical Center, Philadelphia 19104, USA.
Hwang
S N
SN
Ma
J
J
Song
H K
HK
Ford
J C
JC
Haddad
J G
JG
D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D016022:Case-Control Studies; D005260:Female; D005598:Fractures, Spontaneous / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008159:Lumbar Vertebrae / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D011884:Radius / Q000033:anatomy & histology* / Q000473:pathology; D015203:Reproducibility of Results; D016103:Spinal Fractures / Q000175:diagnosis / Q000453:epidemiology